Zero stop mechanism



Feb 1953 T M. A. GOODBAR ET AL 2,628,780

ZERO STOP MECHANISM Original Filed July 17, 1948 FIG. 2

INVENTORS MAYO A. GOODBAR EVERETT H. PLAGKE a CARL G. FOLKNER THEIR ATTORNEYS Patented Feb. 17, 1953 UNITED STATES PATENT OFFICE ZERO STOP MECHANISM Original application July 1'7, 1948, Serial 'No. 39,278. Divided and this application November 14, 1951, Serial No. 256,296

18 Claims. 1

This application is a divisional application oi application Serial No. 39,278, filed July 17,1948, now Patent No. 2,616,638, issued on November 4, 1952.

This invention relates to improvements in zero stop means for differential mechanisms for accounting machines.

The object of the invention is to provide a novel zero stop mechanism for-amount differentials in which the zero stop elements are normally in ineffective positions but :are moved into effective positions by mechanism operated from the main shaft.

Another specific object of the invention is to provide a machine in which the keys on the keyboard have a minimum load to provide a light touch for the keys.

With these and incidental objects in view, the invention includes certain novel features of construction and combinations of parts, a preferred form or embodiment of which is'hereinafter described with reference to the drawing which accompanies and forms a part of this specification.

In the drawing,

Fig. 1 is a side elevational view of the amount differential rack, one bank of amount keys, and a zero stop pawl for controlling the differential movements of the amount differential rack.

Fig. 2 is a side elevational view of the zero stop operating mechanism.

in depressed position.

GENERAL DESCRIPTION The machine in which the present invention is shown applied is .describediin detailin the abovementioned parent case. One of the features .of machine .an easy key action for the .keys of the keyboard, so that va minimum .of pressure is required to depress the .keys. One means of accomplishing this object is the provision .of a novel zero stop means for arresting .the amount differential actuator in zero position. This novel mechanism comprises a zero .stop pawl which is normally in ineffective position, so that, when a key is depressed, thezero stop pawl .need not be moved thereby. When .nokey is depressed, the zero stop pawl is moved into effective position .by mechanism operated from the ,main shaft of the machine at the beginning cfa machine oper ation. Depression of an amount vkey .blocks movement of vthemero stop .paWl during .an operation of the machine, so that, in .an operation during which ;a key ,is depressed, the .zero :stop pawl is held .iniits normal position, to permit the III depressed key to control the movement of the differential actuator.

DETAILED DESCRIPTION Amount My thanks The machine is provided 'with the usual plurality of amount banks. Each bank of amount keys includes a full complement of nine jkeys use, as illustrated in.the parent case. .As fully described .in the parent case, coacting with each bank of amount keys are four control members including a flexible detent, a zero .stop actuating plate 26!, a locking detent 260, .andan interlocking plate that provides a means for preventing the release of themachine by the depression of certain control keys after an amount key has been depressed.

In assembling each key bank, the fourcontrol members, including the zero stop actuating plate .26! are first inserted into the keyboard .frame by being inserted through suitable openings in the front plate I38 and over arow of rods .259, which extend across the entire keyboard, .on which rods the actuator plate 261 slides. The actuator plate .26! is provided with a slot in line with each key shank I06. After the plate is inserted into the keyboard frame, the keys 10B are inserted throughsuitableopenings in the top plate J39 of thekeyboard, then through the slots in the actuator late :26], and through a ro- Fig. 3 is a detail view showingan amount lkey priate slots in the bottom plate I41 of the keyboard frame. By reference to Fig. 1, it will be observed that the keyshanks of the keys I00 are in staggered alinement, and the slots in the keyboard frame and the control members are arranged to register with thekey shanks when the keys are inserted into the key frame. After the keys Hill ,for each digit are assembled into the keyboard frame, a rod 2.58 is inserted through the keyboard frames and through slots provided in the keys.

The rear end of each key is notched, as shown in Fig. 1, to receive the spring I45, which spring stretches across the keyboard frame from right to i left, as viewed from the front of the machine.

The rods 258 limit the upward and downward movements of the keys I00.

Mounted on ears, formed near the front of the keyboard frame, is a zero stop control shaft 216.

a onwhich the zero stops 2', one for each amount bank, are pivotally mounted. The upper end of each zero stop pawl 21! has a finger projecting into a slot of its associated zero control plate 26 l. Also pivotally carried by the shaft .21!) is a yoke 272,.which normally engages the tails on the forward extensions of the zero stop pawls 2', by which the zero stop pawls are controlled, in the manner described hereinafter.

AlVlOUNT DIF *ERENTIAL MECHANISM Located beneath each bank of keys Hill (see Fi l) in a position midway between the staggered keys, and so as to be controlled thereby, is a differential actuator slide Each actuator slide is suitably slotted to be supported by, and slide on, two cross bars 295 and 292, supported in the machine framework. The slide 298 is provided with eight projections along its top edge, having flanges 2S5 bent at right angles thereto, and alternately to the right and left, into aline ment with the shanks of the keys 1%. The flanges 295 are so located on the slide 29% that they are controlled by the digit keys I to 8, respectively. The slide 28%] is provided with a stop surface 256 near its front end, which engages the cross bar 29! to arrest the slide 293 in its 9 position. When no amount key is depressed, a flange 29'! on the zero stop pawl 2?! moves into the path of a flange on the slide 296 to arrest the slide 2% in zero position, which zero position is one step from the home position of the slide. Thus the flanges 2&5 and 293 and the surface 295 provide means to selectively and differentially arrest the slide 290 in any one of ten positions out of its home position, the position 2 to which the slide 299 is moved depending upon whether or not a key has been depressed, or which key has been depresse Thus it is clear that the differential slide 290 is capable of assuming any one of eleven positions; that is, a home position and ten positions of adjustment.

The slide 2610 is provided near its rear end with teeth 3%, meshing with a differential segment 3M, rotatably mounted on a shaft 3623 supported by the framework of the machine. Secured to the segment 31H is an actuator supporting mem her 393. Slidably mounted on the actuator supporting member 3&3 are a plurality of totalizer actuator racks 324, only one of which is shown herein.

As fully described in the parent case, the locking slide 269 maintains the depressed amount key in depressed position.

Upon operation of the machine with an amount key Hill depressed, the actuator slide 293 moves a distance commensurate with the value of the depressed key and, through the teeth 3536, rocks the segment 38l and the actuator supporting member 383 a like distance. This sets the actuator racks 304 an extent representing the value of the depressed key. After the actuators have thus been set, one or more of the totalizers (not shown.) are engaged therewith, and the slide is thereafter returned to its home position. In returning to home position, the segment 30! and the actuators 384 are rotated backwardly a number of steps corresponding to the value of the depressed key, thus entering said amount; in whichever totalizer or totalizers have been engaged therewith. After the amount has been entered therein, the totaliz-ers are from the actuators.

The timing of movement of the differential slide 295 is controlled by a leading frame including a universal rod 3H A spring Bill, secured to the slide 2% at one end, and to a cross plate 338 at its other end, supported by the machine framework, normally maintains a shoulder of the differential slide 293 against the universal rod EHO. The rod 3ll is supported by four arms 3 (only one being shown herein) secured to a shaft 5H2. Also secured to the shaft 3H: are two cam follower arms 35%, each having two rollers Si l coacting with a pair of plate cams 315 secured on the main cam shaft 22$.

During the operation of the machine, the cam plates SIS rotate clockwise (Fig. i) to rock the arms file first clockwise and then counter-clockwise to move the rod 3 l 0 first to the right (Fig. l.) and then back to the left. When the rod 359 moves toward the right, the spring moves the differential slide toward the right until the slide is arrested by a flange thereon coming into contact with a depressed key 5 to 3, or the surface 295 engages the cross bar in the 9 position, or the zero stop pawl. Eli a conipletes its rearward movement. Near the end of the machine operation, when the rod is restored to its home position. by the cams Sid, the rod 3 l 9 picks up the differential slide 2% and restores it to its home position, which position is one step beyond its zero position. During this return, or movement toward home position, the differential slide 293, through the connections described above, rocks the actuator racks backwardly a number of steps commensurate with the value of the depressed key, thus entering the amount into the totalizer wheels which were en gaged therewith.

ZERO STOP IXKECHANLZSM:

A zero stop pawl Eli is provided for each amount difierential to arrest the diiierential slide 29% in the zero position, in the event no amount key is depressed... This Zero stop pawl 2'?! is normally in an ineffective position; that is, the flange 29! thereon is normally out of the path of the flange 298 of the differential slide. The yoke 52, mounted on the shaft 2'58, normally maintains the pawl 2H in said ineiTective position engaging a forwardly-extending toe on the zero stop pawl 27! The yoke 2'52 is maintained its normal position by an arm 326 (Fig. 2) loosely mounted on the shaft 2'50 and having two toes 32! straddling the yoke '52 near its center. The lower end of the arm 328 has mounted thereon a stud 322, which projects into a notch in the forward end of a slide 323 bifurcated to'engage and slide on the cross bar 29E. The rear end of the slide 323 is pivoted to a bell crank 32 pivoted on a shaft 333, said bell crank having a rearwardlyprojecting arm 325 carrying a stud 326 projecting into a notch in the forward end of a lever 32?. The lever 32'! is provided with a roller 3523, which is normally held in engagement with a cam 329 by a spring 339 stretched between one arm of the bell crank 324 and a stud on the lever 32?. The cam 329 is secured to the main cam shaft 2129.

Near the beginning of the operation of the machine, when the main cam shaft 229 and the cam 329 rotate clockwise, the spring 338 rocks the lever 32'! clockwise. This movement of the lever 321, through the bell crank 324, shifts the slide 323 to the left, thus rocking the arm 324! and the yoke 2T2 clockwise. Clockwise movement of the yoke 212 permits the zero stop pawl 21! to be rocked by a spring 33l, to position its flange 291 into the path of the flange 293 on the differential slide 290. The spring 331 is stretched between one end of the zero stop control plate 26I and the keyboard front plate I36. When no key is depressed, the plate 2%! is free to move in the manner described later. When the differential slide 290 is released by movement of the universal rod 3H1, the flange 291, having been 15 :movediinto themath :of the flange .2'9fi,zarrests the :differential slide 32 9.0 inzzero position. .The timing .of this mechanism is T511011 that the scam 31:5 :starts the :slide .290 moving immediately'the zero stop pawl positioned .in its effective :position.

During an operation :of the .machine with :an :amount keydepressed, thezero stopcontrol'plate 26!, coacting with a shoulder 26of the-depressed .key, prevents the :control plate 26 I, .from moving. The control-plate jnturnpreventstheze-ro :stop pawl 2 H fIOmfimOVlIIg .into its :eiTective po- .sition at the time the yoke 21.2 is actuated.

l-By reference to Fig. l, it'can be observedrthat the 9810i: -in-the zero stop-slide .2 6 I through which the amount .key 2100 projects, is long enough to permit free movement of the 'key I00 therein, Without affecting any movementof thenzerostop control plate :26]. :However, when a key .100 is depressed, the upper-shoulder 26 onthedepressed key I00 ;-moves into position to engage the left wall-of the slot .in the control plate 26! to preventeanymovement of thezero stop control plate .261. .The upper end of the :zero stop -pawl 2-H has a toe pro'jecting'into a notch in :therzero .stop control plate #261, .and therefore the *zero istop ,pawl cannot move when released by'the yoke 2.12 whenever a key 1.00 is .depressed and blocks movement of the plate 231.. Therefore, when an amount key is depressed and the plate 28-1 cannot move, the .zerostop .pawl .25 is maintained .in .its Zinefiective position at the time the yoke 212 .is moved by itsacam \329. Under these .condi- .tions, the yoke 212 rocks back .and'forth idly-in the space between the toe on the .zero .stop pawl .21! and its upstandingarm.

Whenno key isdepressed .in the-amount bank, the zerostop control plate 26 I, not being-blocked .by .a shoulder :26 ,of any kev,.-is free to move to the right when the yoke 2 121s rocked. Clockwise rocking movement of the .yoke 212 perm ts the plate 2.6! .to .beso moved by the spring 33! connected to .one end of the :slide. Since .the plate .26I can .now be moved by the spring 331, the zerostop pawl 2.1.1 i .rockedelockwise at the beginning of the machine operation to .lower its, .flange v291 into the path .of the flange298 .onthe" differential slide290.

From the above it .is .clear that the .zero stop gpawl21'l i normally in its upper, orineffective,

position and "is lowered .into an effective .posi- LII .tion .to arrest the difierential slide 2910 only when .nokey is depressed. Depression o'f'thel'kev100 prevents movement of the plate '26! and therefore prevents the zero stop pawl 21! from movinginto its e'ifective position,.thuspermitting the... differential slide to be moved under control of the depressed key.

The above arrangement i novel in that it places 'aminimum'load onthe amountikeys. l-By moving the zero stop pawlby spowersuppliedihy,

the motor, the extra load usually required to move the zero stop pawl by depression .of the "amount keys is eliminated.

While the form of mechanism shown and described herein is admirably adapted to .f-ulfill the objects primarily stated, it is to be understood that it is not intended .to confine the invention to the one form or embodiment disclosed :herein, for .it is susceptible of embodiment various otherforms.

Whatllsclaimedis:

1. In a machineof the class-.de-scribed,the com- .bination of manipulative devices: a differential means controlled by the manipulative devices; a

.zero stop .pawl :normally an ineffective posi- .tioniand movable into :an effectivepositionxtozar- .rest the differential meansiin zero positionpmeans to Jnormally maintain the zero stop pawl in its ineffective position; power-operated means to move the last-named means to release the zero 'stoplpawl to :move into its efiective position .upon initial operation Of :the machine when no manipulative device .is operated; and means .controlled (by an operated "manipulative .device to maintain .the zero stop .pawl innormaliineffective position to permit the differential means to be controlled by an operated manipulative .device during an operation of the machine.

'2. Ina machine of the class described, the combination of manipulative :devices; a, vdiiferenti'al means controlled by the manipulative devices; :a zero stop means to arrest the differential :means in zero position; means to normallymaintain 'the zero 'stop means in an ineffectiveposition; a main shaft; connections between the main shaft and the last-named meansto operate the last named means to release the 'zero stopm'eans to move into a position to arrest the differential 'means in zero position; and means coacting with an operated manipulative device and the new step means to maintain the zero 'stopmeans in rnormal'ineffective position.

In a machine of the class described, the combination of manipulative devices; :a differen- 1 tial IIIHLHS 'COHHOHGdTtQ be set difierentially under control of the manipulative devices; .a .springactuated zero stop pawl movable from a'normal ineffective position into effective position to :ar- 'restthedifferential' means in zero position; means to restrain the zero stop zpawl .in normal r ineffective position when the machine is atrest'; poweroperatedrmeans to move the restraining means during the initial operation of the -machine "to vrelease the :zero stonzpawl to move into-effective position to arrest the differential means in'zero :position; 'and 'a control device connected to the :zero stop pawl. normally free to operate'when the power-operated meams is operated, said manipulativerdevices movable into the normal path of movement of .said control device when the manipulative devices :are .manipulated to arrest themoveinent of the tcontrolidevice thereby maintain the 'zero stop "pawl in its normal :in-

eifective position when the power-operated means is operated.

'4. In a machine of the class :described, the combination of manipulative devices; :a differential:meanscontrolledto be set difierentially unde control of the manipulative devices; a spring actuated zero stop pawl movable from a normal ineffective position into effective position to arrest the-differentialmeansLin zeroposition; means to restrain the zero stcp pawl in ineffective position when-themachine is at :rest; power-operated. means to move therestraining means during initial operation of the machine to release the .2ero:ston {pawl to :move into effectiye position to arrest the rdifierential means in zero position; a :control device connected to the zero stop "ipawl normally free 'to operate when the power-operiated'means in ocerated; "aseries of istopsurfaces en the control device: and a protection on each -manipulative device movable into the path of ".0119 of :said eston'surfaces when "theinanipulative rice is operated to arrest 'zmovement of the control device to maintain the zero stop pawl "in normal ineffective position when the power-roperated means .is .onerated after a manipulative .device .has been operated.

-;.5. in .a machine of the class described, "the combination of manipulative devices; a differential. means controlled to be set differentially under control of the manipulative devices; a springactuated zero stop pawl movable from a normal ineffective position into an effective position to arrest the differential means in zero position; means to restrain the zero stop pawl in ineffective position when the machine is at rest; poweroperated means to move the restraining means during the initial operation of the machine to release the Zero stop pawl to move into effective position to arrest the differential means in zero position; a control device connected to the zero stop pawl normally free to operate when the power-operated means is operated, said control device having a series of openings in which the n .ipulative devices are located and operated; a projection on each manipulative device mo into engagement with a wall of the openin said control device when operated to arrest movement of the control device and the zero stop pawl when the power-operated means is operated.

6. In a machine or" the class described, the combination of manipulative devices; a differential controlled to be set differentially under control of the manipulative devices; a springactuated zero stop pawl movable from a normal ineffective position into an effective position to differential means in zero position; a toe on the zero stop pawl; a bail normally enlng the toe to restrain the zero stop pawl in its ineffective position; power-operated means to roof; the bail upon initial operation of the machine to release the zero stop pawl to move into its effective position; and means coacting with the zero stop pawl and an operated manipulative d vice to restrain the zero stop pawl in ineffective position during machine operation in which a man. ilative device has been operated.

7. In a machine of the class described, the combination of manipulative devices; a differenti ,ans controlled to be set differentially under 01 of the manipulative devices; a spring actuated zero op pawl movable from a normal ineffective no ion into an effective position to arrest the d' ferential means in zero position; a toe on the stop pawl; a bail normally eng ging the toe to restrain the zero stop pawl in ineffective position; power-operated means to rock the bail upon initial operation of the machine; and a control device connected to the stop pawl normally free to operate when the power-operated means operated, said manipulative devices movable into the normal path of movement of said control device when the manipulative devices are manipulated, to arrest the movement of the control device to thereby maintain zero stop pawl in its ineffective position when the ower-operated operated after Inaniput e device is operated.

8. In a machine of the class described, the combination of manipulative devices; a differential means controlled to be set differentially under control of the manipulative devices; a springactuated zero stop pawl having a normal ineffective position and movable into an effective po sition to arrest the differential means in zero position; a toe on the zero stop pawl; a bail normally engaging the toe to restrain the zero stop pawl in its ineffective position; power-operated means to rock the bail upon initial operation of the machine; a control device connected to the zero stop pawl; normally free to operate when the power-operated means is operated; a series of stop surfaces on the control device; and a projection on each manipulative device movable into the path of said stop surfaces when the manipulative device is operated to arrest movement of the control device to maintain the zero stop pawl in normal ineffective position when the poweroperated means is operated after the manipuative device has been operated.

9. In a machine of the class described, the combination of manipulative devices; a differential means controlled to be set differentially under control of the manipulative devices; a springactuated zero stop pawl having a normal ineffective position and movable into an eifective position to arrest the differential means in zero position; a toe on the zero stop pawl; a bail normally engaging the toe to restrain the zero stop pawl in its ineffective position; power-operated means to rock the bail upon initial operation of the machine, said control device having a series of openings in which the manipulative devices are located and operated; and a projection on each manipulative device movable into engagement with a wall of the opening in said control device when operated to arrest movement of the control device and the zero stop pawl when the power-operated means is operated.

10. In a machine of the class described, a plurality of manipulative devices; a differential actuator controlled thereby; a zero stop device having an ineffective position and an effective position for arresting the differential actuator in zero position; and means operable during a machine operation in which a manipulative device is in operated position for maintainng the zero stop device in its ineffective position and operable to move the zero stop device into effective position during machine operations in which no manipulative device is in operated position.

11. In a machine of the class described, a plurality of manipulative devices; a differential actuator controlled thereby; a normally ineffective zero stop device for arresting the differential actuator in zero position; means operable to move the zero stop device into effective position during machine operations in which no manipulative device is in operated position; and means controlled by the operation of a manipulative device to render the last-named means ineffective.

12. In a machine of the class described, the combination of manipulative devices; a differential actuator controlled thereby; a normally ineffective zero stop device for arresting the differential actuator in zero position; a spring to move the zero stop device into effective position; means normally maintaining the zero stop device in ineffective position; and power-operated means to actuate the last-named means to release the zero stop device to the action of the spring, to cause the zero stop device to move into effective position in machine operations in which no manipulative device is in operated position, said the last-named means being held in normal position by an operated manipulative device during operations in which a manipulative device is in operate-d postion.

13. In a machine of the class described, the combination of manipulative devices; a differential actuator controlled thereby; a normally ineffective zero stop device for arresting the differential actuator in zero position; a spring to move the zero stop device into effective position; means to normally maintain the zero stop device in ineffective position; a power-operated means to actuate the last-named means to release the zero combination of manipulative devices; a differ ential actuator controlled thereby; a normally ineffective zero stop device for arresting the difierential actuator in zero position; a spring to move the zero stop device into efiective position; means normally maintaining the zero stop device in ineffective position; a power-operated means to actuate the last-named means to release the zero stop pawl to the action of the spring to cause the I zero stop pawl to move into effective position; a slide connected to the zero stop pawl and disposed yoke to release all the zero stop devices; resilient means to move the released zero stop device into effective positions; and means controlled by the manipulative devices to block movement of the zero stop devices for those blanks of manipulative devices in which a manipulative device has been operated.

17. In a, machine of the class described, the combination of a plurality of banks of manipulative devices; a diiTerential actuator controlled by each bank of manipulative devices; a zero stop device for each bank of manipulative devices and differential actuator; a common yoke member coacting' with the zero stop devices to normally maintain all of the zero stop devices in ineffective positions; a power-operated means to move said yoke to release all the zero stop devices; resilient means to move the released zero stop devices into effective positions; and a slide conin the plane of all of said manipulative devices so as to be controlled thereby; and means on each manipulative device, each movable into the path of said slide to block movement of the zero stop device when the manipulative device is operated combination of a plurality of banks of manipu- 2 lative devices; a differential actuator controlled by each bank of manipulative devices; a zero stop device for each bank of manipulative devices and differential actuator; a common yoke member coacting with the zero stop devices to normally maintain all of the zero stop devices in ineffective position; a power-operated means to move said yoke to release all zero stop devices in machine operations in which no manipulative devices are operated; and resilient means to move the released zero stop devices into effective positions, said resilient means rendered inefiective to move the zero stop devices by the operation of the manipulative devices.

16. In a machine of the class described, the combination of a plurality of banks of manipulative devices; a. differential actuator controlled by each bank of manipulative devices; a zero stop device for each bank of manipulative devices and differential actuator; a common yoke member coacting with each zero stop device to normally maintain all of the zero stop devices in ineffective positions; a power-operated means to move said nected to each zero stop device and coacting with the manipulative devices of each bank of manipulative devices to block movement of the zero stop devices for those banks of manipulative devices in which a manipulative device has been operated.

18. In a machine of the class described, the combination of a plurality of banks of manipulative devices; a differential actuator controlled by each bank of manipulative devices; a zero stop device for each bank of manipulative devices and differential actuators; a common yoke member coacting with the zero stop devices to normally maintain all of the zero stop devices in ineffective positions; a power-operated means to move said yoke to release all zero stop devices; resilient means to move the released zero stop devices into effective positions; a slide connected to each zero stop device; and a lug on each manipulative device movable into contact with the slide associated with its respective bank of manipulative devices to block movement of the zero stop devices for those banks of manipulative devices in which a manipulative device has been operated.

MAYO A. GOODBAR. EVERETT H. PLACKE. CARL G. FALKNER.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,167,714 Goldberg Aug. 1, 1939 

